Conventionally, there is known a wind turbine generator for generating power by using a force of wind as natural energy. In such a wind turbine generator, as the outside air temperature decreases, supercooled water droplets, moisture, or the like in the air collide with wind turbine blades and the like to be frozen, thereby causing icing on the wind turbine blades and the like. For example, Patent Citation 1 discloses a method of detecting icing on a wind turbine generator.
Patent Citation 1: U.S. Pat. No. 7,086,834